Ireland and Ulster are sweating on the fitness of winger Tommy Bowe after he was stretchered off in the Irish province's Heineken Cup clash with Northampton on Saturday.

Ulster lost to the Saints 10-9 in a match which brought an end to their 13-game winning run. The province are still five points clear at the top of their Heineken Cup pool but they face an anxious wait as they determine the nature of Bowe's injury.

The winger looked to suffer a serious knee injury in the closing stages of their match with Northampton as he broke clear in the 77th minute. After a lengthy delay Bowe was stretchered from the field and coach Mark Anscombe admitted post-match that they are worried about just how badly the 28-year-old has injured himself.

"We need to have him scanned to establish the scale of it but it looks serious," Anscombe told the Irish Times. "We will find out more after the scan and see how long he will be out."

Ireland kick-off their Six Nations campaign against Wales on February 2 and Bowe looked set to play a key role in their charge for the northern hemisphere title. Before the international break, Ulster will play their final two matches in the Heineken Cup pool stages and if Bowe's injury is serious, then he will probably miss those games.